Such heads usually have a duct which the liquid sent by the piston flows in, before being dispensed to the outside. At the end of the duct there is usually a nozzle, having many functions. For example, often, the nozzle is made so as to rotate on the duct so that in an open position the liquid may be dispensed outwards and in a closed position, rotated compared to the previous, dispensing is prevented in that the duct is closed.
For greater ease of use, the lateral wall of the nozzle is usually provided with raised captions or symbols defining a functioning configuration.
For example, the document U.S. Pat. No. 6,752,296, illustrates a nozzle in which the captions are raised and are made by overmoulding.
The prior solutions present a number of drawbacks however in that the symbols or captions are not clear or the production costs of the nozzle are high.